plus a copy since you can't do it in place
i was wrong, it is converted in PA
so a copy from program then convert in PA
then comes the cpu intensive part that is maths (il ignore cache trashing since everything trashes cache these days)
per sample it goes, i guess, around 30-60 multiplications and adds
there comes the cpu usage since a multiply for a float is much slower then for an int (add is also slower ofc)
and there is no sse loop for that in "secret rabbit code" so it's all scalar (have not found any in pa either)
also no, gcc does not optimize it into "vectors" (llvm may, idk)
http://www.agner.org/optimize/instruction_tables.pdf if you are interested in how much overhead is that
the floating point in DSP... trend i guess is for another reason, and in my opinion bollocks
people compare a single precision float filter to a 16bit int filter, and ofc the float wins (not by much, nothing you can hear and most of the time even measure)
if they compared it to 32bit integers it would be a different story, one in which int's would win since they have 2^32 precision while floats have... it's complicated
and the whole "modern hardware is so fast" argument is also a load of balls
i have a... idk around 1GHz celeron laptop and 10% cpu usage on it really matters
also there is a good enough sound system in the kernel, OSSv4
also i started a userspace sound server a while ago that may or may not be finished some sunny day
and guess what, no configuration required since it will always play at the highest sampling rate of all the apps using it, dynamically, and the rest will be upsampled
all that with 16.16 bits fixed point integer calculations (so 32bit precision)
should be waaaaaaaay faster then fkin floats with the same, if not better, precision
another thing that wont be a problem is a graphical equalizer since it is practically a required step when resampling (earphone mode too kinda, room speaker placement, etc)
that is what all semi decent windows sound card drivers have been doing for years now, and kids yell "PA is advanced!"
http://www.dspguru.com/dsp/faqs/multirate/resampling is how it is done
and https://ccrma.stanford.edu/~jos/resample/resample.html for more precise theory
good about PA is that they reported bugs when making/maintaining it
and for the couple people with special needs that don't have the knowledge or patience to do it themselves
PS phoronix edit's last for ~30sec for me, even thou it says 5min
No, LFS is not a properly packaged distribution. If you happen to do it correctly, then yes it is, but until it's packaged correctly it's not. Most users do not want to have to mess with their computers, hence why Windows and OS X are so big (they require some tinkering but not of the same difficulty), and why Linux is so small on desktops. When I say don't try to tinker with it, I mean don't expect it to work if you tinker with it. Obviously you can, it's open source, but expect it to break and if it doesn't, good for you. I have met nobody within the past year that has had PulseAudio problems, and myself when I used Linux was one of those people. It was literally one of the things that drove me to Linux, just how good it was and how well it worked without any tinkering whatsoever. I will likely go back to Linux once Wayland is released. NVIDIA driver, PulseAudio (likely Arch Linux), systemd, the whole 9 yards. Will I use it for my everyday tasks including development? Yes. Will I tinker with it at all? Nope. I'll write some systemd conf's but that's the extent of it. Everything else I expect will work perfectly, and if history is any indication of how it will work, it will work fine.
That said, it's the idiots that suggest removing PulseAudio that just confuse me. It's literally one of the driving features for Windows and Mac users, an audio system that requires zero tinkering when used with Ubuntu or Kubuntu (NOW, not 3-4 years ago). Wayland is nice but it's not necessarily a driving force, and the same with systemd.
As far as I've read, MS is going to block access to the Skype Services for older versions of Skype, at least that's what they're planning to do on Windows and Mac, according to german newssite Heise.de. Even if Linux is not directly mentioned, I don't believe it will be any different for us, since MS ist trying to unify MS and Skype Accounts. I personally don't have any problems with pulseaudio, it makes a lot of my tasks easier and works well for me since years, so i don't mind the removal of alsa support. For me as a heavy desktop user and "terminal window collector" everything is fine and dandy, either way.
There was a saying in the 90s that if you built a fool-proof OS only fools would like to use it. Seems like a few are driving Linux from a powerful, power user oriented OS to a dumbed down, fool-proof OS, that only windows/mac users will want to use.
With windows whenever I had one issue (unsupported hardware, crashing stuff, etc.) I always depended on the vendor to solve it if they felt like it. With Linux, usually it was just a question of replacing some app with an alternative, or in extreme cases patching and fixing the code directly. Now? With systemd it is almost impossible to replace it with an alternative. With pulseaudio it isn't like that right now because it was so bad at start that everyone needed to replace it. And for older machines it still adds so much latency that it is best to remove it, independently of your opinion. But that is what the pulseaudio, systemd advocates don't get. There is no "one true way". Power users don't want to be tied to a huge behemoth that tries to do too much, and that is so tied to your system that can't be easily taken out and replaced. It doesn't matter that for 90% of the use cases it works. It is not a desirable solution if it doesn't work for some, and can't be quickly replaced. And dumbing down a power user system to attract windows users will only scare away power users.
Oh well, maybe it is time to move to BSD (even if I prefer the GPL license). It seems like the "dumb it down" crowd is in the majority now.
Windows XP in Virtualbox will be no option. The current versions of Skype don't work in XP, and the older versions will be blocked, so Skype and XP will be a nogo in the future.In that case, I guess I'll have to see if I can get Windows Skype running inside Wine or VirtualBox+WinXP in case I'm not finish ditching it (and MSN Messenger via Pidgin too, I'm guessing) by the cut-off.